Can you put this post of yours in the FAQ? This is something that comes up a lot and is pretty useful. Plus you talked about going more into this in-depth with pics and what not which would be very helpful. I still don't understand why if width isn't that important why time attack and F1 tires are so wide. Or why having a "longer than wide" patch is ideal (at least for the 350z)
"It will have the same contact patch as the thinner wheel/tire...as long as the weight is the same."
exactly, this is why tire sizing(width) is less important than compound for grip. Take for example the acura NSX, an excellent handling car by any measure, ran a 225-50-16 rear tire. Not 'wide' by any strech of the imagination, yet still turned a nice .96g on the skidpad and a great slalom(sp?) speed.
what you really do with a wider tire is make the contact patch wider, instead of longer...which CAN help. It makes the tire itself a bit better at resisting lateral forces(think wide versus narrow stance), and since the contact patch is wider, it makes a higher percentage contact with road...
I'll explain:
think of a gap in the road surface, typically these run perpendiculat to the tires contact patch. in a narro tire, with a long contact patch, the gap in the road surface would take up more(percentage wise) of its contact patch than a wider tire. make sense?
so wider tires do provide some benifit, to a point. Wider tires usually come in stickier compounds, too. The compound and tread design has more to do with tire grip than the size.
hope that helps!also, just FYI the engineer behind the new 350Z chose its tire sizes because the patch would be longer than it was wide, for the vehicles dynamics work better with it that way.
Exar-Kun....
-chet
Check this site out, it has a picture or two and explains about what your talking about. http://www.chris-longhurst.com/carbibles/It's in the tire bible
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Q45tech
- Moderator
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
We teach Masters Degree work here............ "Q45 gave a link to a book on this and I was very interested ... until I found out it was $60. "
Check college text book prices, a $60 book is cheap!
A true enthusiast would have a $1,000 library, [and simple test equipment] it will probably save him [or her] 10-50 times that amount over their driving life!
Just understanding tires and suspensions means you don't fall for all the HYPE........thinking suspension mods do much in the overall scheme of a street car.......thinking lowering helps beyond 3% improvement vs tires which might gain you 10%.......in fractional G's.
People who make their living selling you aftermarket get very creative in finding explanations to confuse you into buying their products [and helping feed their children]..........EDUCATION may not be found on their WEB SITES.
Check college text book prices, a $60 book is cheap!
A true enthusiast would have a $1,000 library, [and simple test equipment] it will probably save him [or her] 10-50 times that amount over their driving life!
Just understanding tires and suspensions means you don't fall for all the HYPE........thinking suspension mods do much in the overall scheme of a street car.......thinking lowering helps beyond 3% improvement vs tires which might gain you 10%.......in fractional G's.
People who make their living selling you aftermarket get very creative in finding explanations to confuse you into buying their products [and helping feed their children]..........EDUCATION may not be found on their WEB SITES.
Exar - OK, I got what he was saying from your original post wich means all my original Q's remain.
Why to F1 and time attack cars have such wide tires if it doesn't matter?
why are fatter tires but in the back on everything from Z's to vett's if it doesn't matter?
and lastly why do "steet perfomance cars" have such thin sidewalls and F1 have so large sidewalls if according to him, less flex is better which would make the case for big wheels and according to some more is sidewall is better for adjustability reasons.
Seems like every question answered brings up two more.
Why to F1 and time attack cars have such wide tires if it doesn't matter?
why are fatter tires but in the back on everything from Z's to vett's if it doesn't matter?
and lastly why do "steet perfomance cars" have such thin sidewalls and F1 have so large sidewalls if according to him, less flex is better which would make the case for big wheels and according to some more is sidewall is better for adjustability reasons.
Seems like every question answered brings up two more.
for the 300zx, vette, etc, the wider tire in the rear of a RWD helps stabilise the rear end against slippage(better lateral stability) in turns, dennis commented on this a while ago, and it helps create more understeer, this is particularly important in heavier cars.
as for the time attack/F-1 car, the actual width of the tire is due to a similar reason, but the design and compound are far more important than width. Some people think lower profile tires will handle better, and someone always points out a f-1 car with a large(relatively) sidewall... there isnt a large relationship between why f-1 runs a wide, tall tire to why a streer car should run a less wide, more stiff tire(lower/stiffer sidewall) so why compare them?
a better comparison would be the ferrari 550 maranello GT-S car, or corvette C5-R. I was astounded that the rear tire width, and sidewall heigh on these cars was supprisingly mediocre(not really, really wide), in fact, I'd think a 265-35-18 would be about the same width that was being run on the 550GTS rears at road atlanta, but I could be msitaken.
did that hlep make sense?-chet
as for the time attack/F-1 car, the actual width of the tire is due to a similar reason, but the design and compound are far more important than width. Some people think lower profile tires will handle better, and someone always points out a f-1 car with a large(relatively) sidewall... there isnt a large relationship between why f-1 runs a wide, tall tire to why a streer car should run a less wide, more stiff tire(lower/stiffer sidewall) so why compare them?
a better comparison would be the ferrari 550 maranello GT-S car, or corvette C5-R. I was astounded that the rear tire width, and sidewall heigh on these cars was supprisingly mediocre(not really, really wide), in fact, I'd think a 265-35-18 would be about the same width that was being run on the 550GTS rears at road atlanta, but I could be msitaken.
did that hlep make sense?-chet
Man... so many questions... I wish we had PM's here. I found another similar (but not quite as exhuastive it seems) book about this and I think I'm gonna brake down and buy it but before I do...
You don't have staggered wheels from what I gather. Is this only for rotational reasons and an inch or so would be benificial or do you think a 240sx would recieve no benifit from this?
lastly, what size tires/wheels do you run and what would you use if money/rotation wasn't a concern. I know power goals are different as well as driving styles so your size might not be the best for me but I'm curious.
You don't have staggered wheels from what I gather. Is this only for rotational reasons and an inch or so would be benificial or do you think a 240sx would recieve no benifit from this?
lastly, what size tires/wheels do you run and what would you use if money/rotation wasn't a concern. I know power goals are different as well as driving styles so your size might not be the best for me but I'm curious.
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lessthanjakejohn
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